[PATCH] kernel/signal: Modify the comment of function check_kill_permission

[zhouchuangao]

Maybe it's easier for us to understand the function of
check_kill_permission.

Signed-off-by: zhouchuangao <zhouchuangao@xxxxxxxx>
---
 kernel/signal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index f2a1b89..2fbf68a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -823,8 +823,10 @@ static bool kill_ok_by_cred(struct task_struct *t)
 }
 
 /*
- * Bad permissions for sending the signal
- * - the caller must hold the RCU read lock
+ * Check if the signal has permission to kill the process.
+ * - The caller must hold the RCU read lock;
+ * - Return 0 means permission is allowed, otherwise returns the
+ *   corresponding error number.
  */
 static int check_kill_permission(int sig, struct kernel_siginfo *info,
 				 struct task_struct *t)
-- 
2.7.4